Motorized wheelchairs presently on the market are generally speaking adapted for movement either along a straight line or around a steered curved arc, somewhat in the same manner as an automobile. If it is desired to realign the wheelchair, for movement from a standing start or fixed position in an entirely new direction, it is generally necessary to go through complex turning manoeuvres, somewhat similar to the "three-point turn" as used in automobiles. These complex manoeuvres are sometimes difficult for disabled persons to carry out. In addition, since such wheelchairs are used indoors (as well as outdoors), the amount of space available for back and forward movement, for making a three-point turn, is often severely restricted.
In addition, existing motorized wheelchairs frequently have difficulty in traversing uneven flooring or terrain and may lose traction, or be somewhat unstable. Another desirable factor in such wheelchairs is the ability of the handicapped person to reach down and pick up something on the floor, or from a low table or shelf. With many designs of wheelchairs this is simply not possible, and the handicapped person is simply obliged to seek assistance from someone else.
Clearly it is desirable to provide such a motorized wheelchair, which can operate from a standing start, and can be directed in any desired direction, without the necessity for a series of forward and reverse movement. It is also desirable to provide such a wheelchair which can adapt itself to changes in the floor height, or terrain. It is also desirable to provide such a wheelchair which can be raised and lowered so as to permit the occupant to pick up objects from the floor, for example, or for any other reason, such as fitting under desks and tables of various heights, and reaching things off shelves and counter tops.
In addition to all of these factors, it is desirable that the chair itself may be capable of swivelling around to face any desired direction.
In addition, since the chair must be operated by a handicapped or disabled person, the controls should be of the utmost simplicity, and be capable of being operated by a single hand, or by some other means without any dexterity being required. It should be possible to interconnect with various different controls used by disabled people such as head rests fitted with switches and voice controls. It should be possible to program different performance features such as maximum speed and acceleration to match the capabilities of users with various physical and cognitive abilities.